MAO Inhibitor Medications
The monoamine oxidase inhibitors (MAOIs) used for treatment-resistant or atypical depression and certain anxiety disorders include phenelzine, isocarboxazid, tranylcypromine, and moclobemide. 1
Available MAOI Medications
The specific MAOIs mentioned in clinical guidelines are:
- Phenelzine - A non-selective MAOI effective for treatment-resistant and atypical depression 1, 2, 3
- Isocarboxazid - A non-selective MAOI used in treatment-resistant cases 1, 4
- Tranylcypromine - A non-selective MAOI with efficacy in treatment-resistant and atypical depression 1, 5, 3
- Moclobemide - A reversible MAO-A inhibitor (RIMA) with better tolerability 1, 2, 6
Important Context About MAOI Use
These medications are typically considered third-line treatments for depression, reserved for patients who have failed to respond to SSRIs, SNRIs, and other first- and second-line antidepressants 6, 3, 7. The non-selective agents (phenelzine, tranylcypromine, isocarboxazid) have distinctive efficacy in atypical depression and treatment-resistant depression, though they come with significant tolerability concerns including dietary restrictions and drug interaction risks 3.
Moclobemide is not available in Japan or the United States but is used in other countries and has a more favorable safety profile as a selective, reversible MAO-A inhibitor 2.
Additional MAOI-Related Agents
The guidelines also mention:
- Selegiline (transdermal system) - A selective MAO-B inhibitor approved for depression at higher doses 8
- Isoniazid and linezolid - These are noted as having MAOI properties but are primarily antimicrobial agents, not antidepressants 1
Critical Safety Consideration
MAOIs are contraindicated in combination with SSRIs, SNRIs, and most other serotonergic medications due to severe risk of serotonin syndrome, which can be fatal 1. A washout period is mandatory when switching between these medication classes.